To salt or not to salt? | Living Green | willistonobserver.com

Ice-melting salt is useful in winter but can pollute soil and water

The United States uses an estimated 20 million metric tons of salt on roads every year.

In places like the Lake Champlain basin, the long, cold winters mean a lot of salt applied on our roads and sidewalks. But all of that salt can pollute our soils and waters and harm local ecosystems.

“Road salt can make its way via streams to local lakes and ponds,” said Kris Stepenuck, associate director of the Lake Champlain Sea Grant, a program of UVM that produces scientific work to benefit the Lake Champlain basin. “Once there, it will only accumulate and can cause unsafe — or even toxic — conditions for fish and other aquatic life.”

What can you do to protect local forests and waterways when using ice-melting salt? Follow these guidelines.

Check to see if the conditions are right

Salt depresses the freezing point of water, which makes it effective at reducing ice formation and accumulation on streets and sidewalks in the winter—down to a certain temperature. Sodium chloride, the most common type of road salt, is not effective when the pavement temperature is colder than around 16 degrees.

So, be sure to check the temperature of the pavement with an infrared thermometer before you salt. If it’s too cold, opt for an alternative such as gravel, sand or even cat litter. These materials will provide extra traction to help prevent slipping while also absorbing more heat from sunlight, which helps melt the snow.

If your driveway is gravel or dirt, applying salt is even more harmful for the environment and can cause dangerous conditions for driving. Instead, try salt alternatives like gravel, sand or cat litter to increase traction.

Salt before the snow

So, you’ve just checked the forecast to see if it’s the right temperature to apply salt and saw a big storm rolling in. What can you do? If you salt before the storm, it provides a buffer between your driveway and the snow, which makes shoveling easier and driving safer.

Bonus points if you dissolve the salt in water first and spray the mixture on your driveway.

“Using a 23 percent salt-water solution acts like butter in a frying pan,” Stepenuck said. “This reduces the ability of snow and ice to bond with the surface. Using a salt-water mixture can reduce total salt use and make it easier to plow or shovel after the storm. Plus, since any dry salt you spread must combine with water to minimize ice formation, the mixture can work its magic more quickly than if you spread dry salt.”

Shovel, then salt

If you apply salt to your driveway when it already has a layer of snow on it, the salt will need to seep through the layer of snow before it can start working, meaning you would need more salt to keep the driveway free from snow and ice. Instead, shovel first and apply the salt as close to the pavement as you can.

Use the right amount

Salt is often spread on driveways and sidewalks without much rhyme or reason, but the amount of salt you use matters. A good rule of thumb is to spread no more than a cup or a cup and a half of rock salt for every 10 sidewalk squares or every two parking spaces. There should be about 3 inches between each of the salt grains.

Using more than that doesn’t make it more effective, it just allows more salt to runoff into the environment, to be tracked into the house or to damage doors, steps or other structures. And it wastes money.

If you used too much salt and see it on your driveway or walkways after the snow is gone, sweep it up. You can save it and use it for the next storm. Otherwise, this excess salt will slowly infiltrate into the soil around it or run off your driveway, ultimately polluting a nearby waterway.

Tell your neighbors

The best way to increase your impact is to get other people on board. Share these tips with your friends and neighbors so that we can all have a safe and sustainable winter. Happy shoveling!

 For more information, email seagrant@uvm.edu.